Device for equalizing fluctuations produced in masses delivered by spinning pumps



Nova 12, 1935. H DANNENBERG 2,020,633

DEvIcE FOR EQUALIZING FLUCTUATIONS PRODUCED IN MASSES DELIVERED BY SPINNING PUMPS Filed Oct. 19, 1952 fig. 2

In vemor:

By Aflorneys Patented Nov. 12, 1935 UNITED STATES PATENT OFFICE DEVICE FOR EQUALIZING FLUCTUATIONS PRODUCED IN MASSES DELIVERED BY SPINNING PUBIPS Application October 19, 1932, Serial No. 638,655 In Germany October 23, 1931 2 Claims.

The pumps used for supplying the spinning solution in the manufacture of artificial silk often suffer from the drawback that the flow of the spinning solution is not uniform but shows one or several maxima and minima in each revolution of the pump. This is particularly the case with piston pumps, but pumps of other kinds are also not free from this drawback.

Attempts to equalize the fluctuations in the delivery of the solution by arranging an air chamber in the duct between the spinning pump and the spinning nozzle have involved the drawback that the air contained in the chamber is gradually absorbed by the spinning solution and the equalizing effect is in consequence decreased. It has therefore been suggested to use as an equalizing means an elastic or resilient membrane or hollow body. When there is used a device of this kind, however, it is very difficult to avoid dead spaces in which the spinning solution sets and hardens.

Reference is made to the accompanying drawing in which Fig. 1 shows a section through an arrangement according to this invention,

Fig. 2 represents a diagram showing the fluctuations in the spinning solution produced by a three-piston pump, and

Fig. 3 shows a diagram under the same conditions but with a device according to this invention.

The object of this invention is to provide means for equalizing variations in the rate of flow of spinning solutions delivered by the pump 5 while avoiding any disturbances. According to the invention the duct which conveys the spinning solution from the pump to the spinning nozzle comprises a portion consisting of a thickwalled rubber tube of high elasticity. The tube is made of such material and of such dimensions that it is under considerable tension owing to the pressure prevailing within the duct, without, however, being constantly inflated. It should have a bore which is less than the thickness of its walls. It has been found that such a tube responds even to slight variations in the rate of flow of the solution passing through it and becomes inflated or deflated correspondingly, thus equalizing the fluctuations in the pressure and the quantity of solution delivered per unit time.

The dimensions of the tube are selected according to the pressures which occur and the viscosities of the spinning solutions.

For protecting the tube from overcharge due, for instance, to obstruction of the nozzles, and 5 from external influences it is advantageous to enclose it within another tube of a suitable. material, for instance, iron or glass, which has a somewhat larger diameter, and is not air-tight, or within a loosely fitting spiral or any other 1 similar device. An excessive pressure merely presses the tube against the protective device and its compensating action is suspended while this pressure prevails.

The invention will be more intelligible by ref- 15 erence to the accompanying drawing. The spinning solution enters the spinning pump by the feed pipe and the pump fittings. The spinning pump, for instance, a three-piston pump conveyes the spinning liquid to the filter candle 20 and the spinning nozzles. The spinning pump and filter fittings within which the filter candle is mounted are connected by means of jet pipes to a tube of rubber which is surrounded by a protecting spiral. The inner diameter of the protecting spiral is somewhat wider than the outer diameter of the rubber tube. The rubber tube is fastened on the jet pipes by means of clamps.

The improvements attained by the device described are illustrated in the accompanying drawing in which Fig. 2 shows the fluctuations in the rate of delivery of a spinning solution by a normal three-piston pump in the course of three revolutions, and Fig. 3 shows the fluctuations produced under the same conditions when there is used a tube according to this invention. It will be seen that apart from very slight variations the fluctuations have almost disappeared.

The following example illustrates the invention:

A rubber tube of length 20 cm. of bore 3 mm. and external diameter 21 mm. is inserted so as to form part of the duct connecting the pump and the spinning nozzle and surrounded by a 5 spiral of steel wire having an inner diameter of 22 mm. and a pitch of 5 mm. the thickness of the wire being 2 mm.

What I claim is:

1. A device for equalizing variations in the 50 rate of flow of a spinning solution delivered by the spinning pump to the spinning nozzle which comprises a thick-walled rubber tube forming a part of the duct conveying the solution from the pump to the nozzle, said rubber-tube having a wall thicker than its bore and its exterior subject to atmospheric pressure.

2. A device for equalizing variations in the rate of flow of a spinning solution delivered by 10 the spinning pump to the spinning nozzle which comprises a thick-walled rubber tube forming a part of the duct conveying the solution from the pump to the nozzle, said rubber-tube having a wall thicker than its bore and its exterior subject to atmospheric pressure, and a. wire spiral surrounding said rubber-tube and having an inner diameter substantially larger than the thickness of the rubber tube.

HANS DANNENBERG. 

